A Shanghai research team has developed a waterborne automotive coating made from carbon black pigment and carbon nanotubes. The work was led by Zhiwei Liu, a research chemist with NIPSEA Group’s Color Technology, Group Core R&D Shanghai unit.
The composite absorbed an average of 99.90% of visible wavelengths in the researchers’ measurements. They incorporated it into a coating binder and sprayed it onto an automotive model, creating an extremely deep black finish while using a process closer to conventional vehicle painting than vertically aligned nanotube coatings.
The result is still a proof of concept, not a production-car finish. Ultra-black surfaces can suppress the reflections that normally reveal curves and panel lines, but the researchers also used a glossy clearcoat to return some visible shape to the model.
What 99.9% actually looks like
The difference between ordinary black paint and an ultra-black surface sounds tiny when expressed as an absorption percentage. Conventional black automotive paint can reach around 99.8% light absorption, while the Shanghai composite averaged 99.90% across visible wavelengths.
What matters visually is the small fraction of light that escapes. Reflections and highlights allow the eye to trace a curved fender, a crease in a door, or the edge of a hood, so reducing those signals can make a three-dimensional object appear unusually flat.
BMW demonstrated the principle in 2019 with a one-off X6 finished in Vantablack VBx2. The company said the coating caused surfaces to lose defining visual features and made objects appear two-dimensional.
That comparison needs one important qualification. BMW reported that VBx2 had 1% total hemispherical reflectance, so the X6 was not coated in the original 99.965%-absorbing Vantablack material often cited in descriptions of the world’s darkest coatings.
How the hybrid coating works
The Shanghai team combined carbon black, a common pigment used in products including coatings and tires, with carbon nanotubes. According to TechSpot’s review of the paper, a natural pi-interaction between the two carbon materials helps organize the particles into a connected structure.
Carbon black provides strong intrinsic absorption, while the nanotube-supported structure creates additional paths in which light can scatter before being absorbed. The researchers described the resulting material as having a structural light-trapping morphology rather than relying only on a larger quantity of black pigment.
This distinction is central to the work. Instead of growing a delicate forest of vertically aligned nanotubes directly on a surface, the team placed nanotubes and carbon-black particles inside a waterborne coating system that could be sprayed onto a model.
What the durability tests showed
The researchers exposed coated panels to two accelerated environmental tests. One sample remained in a 40°C water bath for 10 days, while another spent 14 days in 95% humidity.
The researchers reported no significant visible paint defects after those tests. The samples also passed a cross-cut adhesion assessment, in which a grid is cut into the coating and tape is used to check whether sections detach.
Those results address water resistance, humidity resistance, and adhesion under the conditions tested. They do not amount to complete automotive qualification, which would require a broader program covering application consistency and the full range of film-performance requirements.
Why the glossy layer matters
An extremely matte ultra-black surface removes many of the highlights that communicate shape. That visual effect is dramatic on a display object, but it can hide the sculpted details that automotive designers normally want customers to see.
The researchers therefore placed a transparent glossy clearcoat over the ultra-black base layer on their automotive model. Specular highlights from that upper layer restored visible reflections along the model’s curves while the basecoat maintained a deeper black appearance underneath.
This means the finished system should not be described as a uniformly light-swallowing void. Its appearance depends on the combination of the absorbing basecoat, the glossy upper layer, the viewing angle, and the available light.
Why the researchers pursued an automotive finish
Liu said vehicle color has become an important selling point in China and that deep-black finishes are associated with luxury vehicles. The project was therefore designed around automotive requirements rather than darkness alone.
That helps explain the emphasis on a waterborne binder, spray application, humidity resistance, and adhesion. An optical record would have limited commercial value if the coating could not be processed or remain attached under the conditions expected of vehicle paint.
What the study does not yet prove
The available research does not show a full-size vehicle undergoing road, weather, abrasion, crash-repair, or long-term outdoor testing. It also does not establish how the finish would affect vehicle visibility at night or in poor weather.
Those questions should therefore remain open rather than being answered speculatively. The researchers themselves said further work is needed to establish the usable application window and validate the coating’s complete film performance before ultra-black cars using it could reach public roads.
Ultra-black beyond cars
Ultra-black coatings already serve less theatrical purposes in optical and aerospace systems. Surrey NanoSystems’ technical material for Vantablack S-VIS lists optical baffles, blackbody calibration systems, infrared imaging equipment, and lens assemblies among its application areas.
In those settings, absorbing stray light can improve contrast or reduce unwanted reflections inside an instrument. The Shanghai study did not qualify its new composite for space or scientific instruments, however, so those established applications should be treated as context rather than as proven markets for this particular coating.
The optical race
Surrey NanoSystems says Vantablack can absorb up to 99.965% of light. The Shanghai composite’s reported average of 99.90% is slightly lower, but its intended advantage is the possibility of combining extreme absorption with waterborne automotive processing and tested environmental resistance.
In 2019, an MIT team reported a vertically aligned carbon-nanotube material that captured at least 99.995% of incoming light. That material used nanotubes grown on chlorine-etched aluminum foil, making it a different system with different manufacturing constraints.
Numbers from these materials should not be treated as a simple league table without considering the measurement method, wavelength range, substrate, application process, and required durability. For automotive use, the darkest laboratory sample is not automatically the most useful coating.
What happens next
The research establishes a technical proof of concept for a spray-applied, carbon-black and carbon-nanotube automotive coating. It does not establish a launch date, commercial price, regulatory status, or production partnership with an automaker.
Future work will focus on defining a reliable application window and validating the complete performance of the coating film. Until then, the most significant result is not a car disappearing into the dusk, but a laboratory coating moving one step closer to combining ultra-black optics with the practical demands of automotive paint.
